I am building the store as a json store. Right now I have it pointing at nothing. Should I create an empty file to point at?

I'd like to build a variable up within my application (add and removing items to it as required) and then point to that variable as the store. I basically want to grab the most recent data and populate it within a list that would access the store.

I then create a json array within my controller to keep track of changes.

From your comment, I'm obviously going about it completely wrong. Can you steer me in the right direction?
What I'm trying to achieve is to build a "bread crumb" to allow the user to go back within the navigation view (and pop off the views until the clicked on view was visible) and my first thought was this could be achieved by using a horizontal list.

Right now I suppose I'm not really creating a store at all. I've got a json variable in my controller that I'm populating with data, that I'd like to reference as the store. I could create an empty file on disk to point at if that is a reasonable starting point?
I push data to the json variable with MyJsonVar.push(newdata);

However, store returns as undefined. This is why I wonder if I can in fact do what I'm trying to accomplish.
I looked at the Categories store - it doesn't have an id or xtype, so I'm confused how the reference is working there, but not in my code. Obviously I'm overlooking something...